There is often the requirement to mount or attach equipment to a structure, such as for example electrical equipment in a rack. The racks normally are formed from 2 or 4 vertical elongate structures to form a cabinet type arrangement. Such racks are or can be closed on 3 or more sides, and the front side can have a door. As such, while it is possible to access any side by removing panels or similar it is often inconvenient, at least a time perspective. As such front access for install and removal of equipment and its fastening is the most desirable and convenient. The back side is normally reserved for electrical and network connections and similar.
The two structures that form the front of the rack normally have a series of spaced apertures on the front presenting vertical face. These apertures are to secure, via fasteners, the equipment to the rack. The access to these apertures is normally only from this front, as access from the rear is either blocked by the or other equipment, or is too difficult. Side access is often blocked by side panels that enclose the rack, or is otherwise inconvenient.
Then adding or removing equipment to the rack it is desirable this can be achieve as quickly as possible. This may be desirable because systems need to be powered down before equipment is added or removed, or because there is a short time frame to add or remove the equipment. It is also desirable to make the mechanical physical fastenings, convenient and as secure but as quick as possible.
There is therefore the need for a fastener for use where it is convenient or only possible, to access one side, that is the front side for example, of equipment that needs fastening to such structures or racks. This is opposed to a normal fastener arrangement where, for example, a user passes a bolt through one side and fastens a nut to it on the other.
The modularity of such racks and the equipment connected thereto has resulted in a number of solutions to this problem for rack mounting in the telecommunications, IT, security and professional audio industries.
A captive fastener solution is shown in U.S. Pat. No. 6,682,282 and US20050019133. This shows a captive bolt of one thread size which can be switched for a bolt of another thread size by releasing the bolt from a removable retainer. They are used for fastening rack mount panels to equipment racks. These solutions at least have the disadvantage that they must be supplied already attached to the equipment to be installed. Thus whilst they are always attached to the equipment, there will be surplus such fasteners, for example sitting on equipment that is not installed. They also require custom mounts and therefore are not readily adaptable or transferable between pieces of equipment.
Other solutions to aid the accessibility issue are blind nuts to sit behind the front face of the structure such as that shown in U.S. Pat. No. 6,538,894 for a front insertion fastener. This shows a front inserted nut that deforms to capture the structure between a front flange and rear wings that deform laterally to the main axis of the nut. The front flange has a return to engage with the structure edge to reduce rotation while tightening. The rear portion of the nut has a flange that engages with the rear side of the structure also due in part to deformation. Such solutions remove or reduce the need to access the rear of the structure. However, because they deform plastically and therefore permanently they present difficulty in removing in the same way they are inserted and may not be reusable. Such blind or captive nuts also have the disadvantage as they can easily be lost down or within the rack. These also often require specialist tools to install and remove.
A latch style fastener is shown in GB 1123733 where a knurled knob operates a latch tongue to engage and disengage the equipment from the structure. This is an easy way to engage and disengage the equipment from the rack. However, it again requires specialist fitting on the equipment and/or the rack.
Side mounting and engaging equipment is shown in U.S. Pat. No. 6,353,542. This shows a rack mounting bracket for mounting heavy unbalanced equipment. This rack mounting system is for either side of a piece of equipment that clamps the racks. This system holds the equipment securely but requires additional brackets, has added clearance and bulk issues and may require access from the side.
A number of these solutions also have sharp edges so they can easily damage equipment that is slide in and out past them, especially when the equipment is heavy and/or the rack is high populated with little room to move.
These solutions also require a degree of balancing equipment while other fasteners are brought into location to mount the equipment. This is undesirable when the equipment is heavy or the rack is populated and can result in equipment damage and/or operator injury.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.
It is an object of the present invention to provide an improved fastener, or to overcome the above shortcomings or address the above desiderata, or to at least provide the public with a useful choice.